Electro-magnetically induced transparency (EIT) provides a mechanism for controlling bi-directional light propagation in a dielectric medium. EIT traditionally typically arises from destructive interference induced by a non-radiative coherence in an atomic system. EIT-type processes based on SBS include a magneto-optical element, e.g., electromagnetic power and/or magnets, and have been considered infeasible because of the short coherence lifetime of hypersonic phonons.